NU 545 Unit 2-QUESTIONS WITH ALL
CORRECT ANSWERS!!
Review the anatomy of the brain. Which portion is responsible for keeping you awake,
controlling thought, speech, emotions and behavior, maintaining balance and posture?
The reticular formation is a large network of diffuse nuclei that connect the brainstem to the
cortex and control vital reflexes. It is essential for maintaining wakefulness and is referred to as
the reticular activating system. Some nuclei within the reticular formation support specific motor
movements, such as balance and posture (p448). The cerebellum is responsible for maintaining
balance and posture (p452). The prefrontal area is responsible for the elaboration of thought (pg
449). The Broca speech area is on the inferior frontal gyrus (Brodmann 44, 45). It is usually on
the left hemisphere and is responsible for motor aspects of speech. Broca Area in the inferior
frontal lobe (Brodmann areas 44, 45) is an important center for speech and language processing.
This area, rostral to the inferior edge of the premotor area (Brodmann area 6). Injury to this area
results in difficulty forming or inability to for words (expressive aphasia or dysphasia). Wernicke
(posterior Brodmann 22) and adjacent portions of the parietal lobe are a sensory speech area,
responsible for reception and interpretation of speech (aphasia/dysphasia). Insula (insular lobe)
between hemispheres temporal and frontal lobes, processes emotional information (pg 450). The
basal ganglia nuclei are important for emotional functions (pg 451). Cerebrum >
forebrain/hindbrain
Broca's area = difficulty writing and finding words, See chart 17.10 (p523)
Know the function of the arachnoid villi.
,The arachnoid villi protrude from the arachnoid space, through the dura mater, and lie within the
blood flow of the venous sinuses. The villi function as one-way valves directing CSF outflow
into the blood but preventing blood flow into the subarachnoid space. Thus CSF is formed from
the blood and, after circulating throughout the CNS, it returns to the blood. Absorbs CSF (pg
459)
Where is the primary defect in Parkinson's disease and Huntington's?
Extrapyramidal system; controls motor system (involuntary movement) (pg 451). Substantia
nigra (of the midbrain) synthesizes dopamine. The dysfunction of dopamine neurons is
associated with PD and Huntington's
What is the function of the CSF? Where is it produced? Where is it absorbed?
Cerebrospinal fluid (CSF) is a clear, colorless fluid similar to blood plasma and interstitial fluid.
The intracranial and spinal cord structures float in CSF and are thereby partially protected from
jolts and blows. The buoyant properties of the CSF also prevent the brain from tugging on
meninges, nerve roots, and blood vessels. Appx 600mL is produced daily (457). Ependymal cells
in the choroid plexuses are the structures that produce CSF; they arise from the pia mater. The
arachnoid villi reabsorb the CSF (p458)
Review blood flow to the brain.
The brain receives approximately 20% of the cardiac output, or 800 to 1000 mL of blood flow
per minute. Autoregulated to maintain a stable flow during fluctuating perfusion pressures.
Carbon dioxide serves as a primary regulator for blood flow within the CNS. It is a potent
vasodilator in the CNS, and its effects ensure an adequate blood supply. The brain derives its
arterial supply from the internal carotid arteries (anterior circulation) and the vertebral arteries
,(posterior circulation) (Fig. 15.20). The internal carotid arteries supply a proportionately greater
amount of blood flow. They originate at the common carotid arteries, enter the cranium through
the base of the skull, and pass through the cavernous sinus. After entering the skull, these arteries
divide into the anterior and middle cerebral arteries (Fig. 15.21). The vertebral arteries originate
at the subclavian arteries and pass through the transverse foramina of the cervical vertebrae,
entering the cranium through the foramen magnum. They join at the junction of the pons and
medulla oblongata to form the basilar artery. The basilar artery divides at the level of the
midbrain to form paired posterior cerebral arteries (459). When one of the routes is obstructed,
the circle of Willis is an alternate route.
What is the gate control theory of pain?
Gate control theory (GCT) integrates and builds upon features of the other theories to explain the
complex multidimensional aspects of pain perception and pain modulation. Pain transmission is
modulated by a balance of impulses conducted to the spinal cord where cells in the substantia
gelatinosa function as a "gate." The spinal gate regulates pain transmission to higher centers in
the CNS. Large myelinated A-delta fibers and small unmyelinated C fibers respond to a broad
range of painful stimuli (mechanical, thermal, and chemical). These fibers terminate on
interneurons in the substantia gelatinosa (laminae in the dorsal horn of the spinal cord) and
"open" the spinal gate to transmit the perception of pain. Closure or partial closure of the spinal
gates can occur from nonnociceptive stimulation (i.e., from touch sensors in the skin) carried on
large A-beta fibers decreasing pain perception.
The theories of pain include the specificity theory, pattern theory, gate control theory, and
neuromatrix theory. 4 Specificity theory proposes that pain and touch are carried on distinct
pathways that project to distinct brain centers. Injury activates only specific pain receptors and
, fibers that project to the brain. Intensity of pain is directly related to the amount of associated
tissue injury (i.e., pricking one's finger with a needle would cause minimal pain, whereas cutting
one's hand with a knife would produce more pain). The theory is useful when applied to specific
injuries and the acute pain associated with them. It does not account for chronic pain or cognitive
and emotional elements that contribute to more complex types of pain. 5
Know the type of nerve fibers that transmit pain impulses. Page 470
Transduction begins when nociceptors are activated by a painful stimulus causing ion channels
to open, creating electrical impulses that travel through axons or two primary types. Pain
impulses are conducted along the A-delta and C fibers of nociceptors.
A-delta fibers: larger myelinated fibers that rapidly transmit sharp, well-localized "fast"
sensations (intense heat or pinprick) "reflex"
· stimulated by mechanoreceptors and mechanothermal nociceptors
· Responsible for causing reflex withdrawal of the body from the painful stimulus
C Fibers: most numerous, smaller, unmyelinated, slowly transmit dull, aching, burning
sensations that are poorly localize and constant
· Stimulated by mechanical, thermal, and chemical nociceptors
A-beta fibers: NOT responsible to transmit pain, but play a role in pain modulation. Large,
myelinated fibers that transmit touch & vibration (p475)
Where in the CNS does pain perception occur?
Pain perception occurs primarily in the reticular and limbic systems and the cerebral cortex
(p476)
It is the conscious awareness of pain; requires the interaction of three systems:
CORRECT ANSWERS!!
Review the anatomy of the brain. Which portion is responsible for keeping you awake,
controlling thought, speech, emotions and behavior, maintaining balance and posture?
The reticular formation is a large network of diffuse nuclei that connect the brainstem to the
cortex and control vital reflexes. It is essential for maintaining wakefulness and is referred to as
the reticular activating system. Some nuclei within the reticular formation support specific motor
movements, such as balance and posture (p448). The cerebellum is responsible for maintaining
balance and posture (p452). The prefrontal area is responsible for the elaboration of thought (pg
449). The Broca speech area is on the inferior frontal gyrus (Brodmann 44, 45). It is usually on
the left hemisphere and is responsible for motor aspects of speech. Broca Area in the inferior
frontal lobe (Brodmann areas 44, 45) is an important center for speech and language processing.
This area, rostral to the inferior edge of the premotor area (Brodmann area 6). Injury to this area
results in difficulty forming or inability to for words (expressive aphasia or dysphasia). Wernicke
(posterior Brodmann 22) and adjacent portions of the parietal lobe are a sensory speech area,
responsible for reception and interpretation of speech (aphasia/dysphasia). Insula (insular lobe)
between hemispheres temporal and frontal lobes, processes emotional information (pg 450). The
basal ganglia nuclei are important for emotional functions (pg 451). Cerebrum >
forebrain/hindbrain
Broca's area = difficulty writing and finding words, See chart 17.10 (p523)
Know the function of the arachnoid villi.
,The arachnoid villi protrude from the arachnoid space, through the dura mater, and lie within the
blood flow of the venous sinuses. The villi function as one-way valves directing CSF outflow
into the blood but preventing blood flow into the subarachnoid space. Thus CSF is formed from
the blood and, after circulating throughout the CNS, it returns to the blood. Absorbs CSF (pg
459)
Where is the primary defect in Parkinson's disease and Huntington's?
Extrapyramidal system; controls motor system (involuntary movement) (pg 451). Substantia
nigra (of the midbrain) synthesizes dopamine. The dysfunction of dopamine neurons is
associated with PD and Huntington's
What is the function of the CSF? Where is it produced? Where is it absorbed?
Cerebrospinal fluid (CSF) is a clear, colorless fluid similar to blood plasma and interstitial fluid.
The intracranial and spinal cord structures float in CSF and are thereby partially protected from
jolts and blows. The buoyant properties of the CSF also prevent the brain from tugging on
meninges, nerve roots, and blood vessels. Appx 600mL is produced daily (457). Ependymal cells
in the choroid plexuses are the structures that produce CSF; they arise from the pia mater. The
arachnoid villi reabsorb the CSF (p458)
Review blood flow to the brain.
The brain receives approximately 20% of the cardiac output, or 800 to 1000 mL of blood flow
per minute. Autoregulated to maintain a stable flow during fluctuating perfusion pressures.
Carbon dioxide serves as a primary regulator for blood flow within the CNS. It is a potent
vasodilator in the CNS, and its effects ensure an adequate blood supply. The brain derives its
arterial supply from the internal carotid arteries (anterior circulation) and the vertebral arteries
,(posterior circulation) (Fig. 15.20). The internal carotid arteries supply a proportionately greater
amount of blood flow. They originate at the common carotid arteries, enter the cranium through
the base of the skull, and pass through the cavernous sinus. After entering the skull, these arteries
divide into the anterior and middle cerebral arteries (Fig. 15.21). The vertebral arteries originate
at the subclavian arteries and pass through the transverse foramina of the cervical vertebrae,
entering the cranium through the foramen magnum. They join at the junction of the pons and
medulla oblongata to form the basilar artery. The basilar artery divides at the level of the
midbrain to form paired posterior cerebral arteries (459). When one of the routes is obstructed,
the circle of Willis is an alternate route.
What is the gate control theory of pain?
Gate control theory (GCT) integrates and builds upon features of the other theories to explain the
complex multidimensional aspects of pain perception and pain modulation. Pain transmission is
modulated by a balance of impulses conducted to the spinal cord where cells in the substantia
gelatinosa function as a "gate." The spinal gate regulates pain transmission to higher centers in
the CNS. Large myelinated A-delta fibers and small unmyelinated C fibers respond to a broad
range of painful stimuli (mechanical, thermal, and chemical). These fibers terminate on
interneurons in the substantia gelatinosa (laminae in the dorsal horn of the spinal cord) and
"open" the spinal gate to transmit the perception of pain. Closure or partial closure of the spinal
gates can occur from nonnociceptive stimulation (i.e., from touch sensors in the skin) carried on
large A-beta fibers decreasing pain perception.
The theories of pain include the specificity theory, pattern theory, gate control theory, and
neuromatrix theory. 4 Specificity theory proposes that pain and touch are carried on distinct
pathways that project to distinct brain centers. Injury activates only specific pain receptors and
, fibers that project to the brain. Intensity of pain is directly related to the amount of associated
tissue injury (i.e., pricking one's finger with a needle would cause minimal pain, whereas cutting
one's hand with a knife would produce more pain). The theory is useful when applied to specific
injuries and the acute pain associated with them. It does not account for chronic pain or cognitive
and emotional elements that contribute to more complex types of pain. 5
Know the type of nerve fibers that transmit pain impulses. Page 470
Transduction begins when nociceptors are activated by a painful stimulus causing ion channels
to open, creating electrical impulses that travel through axons or two primary types. Pain
impulses are conducted along the A-delta and C fibers of nociceptors.
A-delta fibers: larger myelinated fibers that rapidly transmit sharp, well-localized "fast"
sensations (intense heat or pinprick) "reflex"
· stimulated by mechanoreceptors and mechanothermal nociceptors
· Responsible for causing reflex withdrawal of the body from the painful stimulus
C Fibers: most numerous, smaller, unmyelinated, slowly transmit dull, aching, burning
sensations that are poorly localize and constant
· Stimulated by mechanical, thermal, and chemical nociceptors
A-beta fibers: NOT responsible to transmit pain, but play a role in pain modulation. Large,
myelinated fibers that transmit touch & vibration (p475)
Where in the CNS does pain perception occur?
Pain perception occurs primarily in the reticular and limbic systems and the cerebral cortex
(p476)
It is the conscious awareness of pain; requires the interaction of three systems:
